To look through the mentioned concepts in detail, we consider the conventional PAC-Bayes bound in [1]}. In [1]}, by setting \(\mathrm {F}^{\textup {Task}} \left(a,b\right)=2(\mathrm {M}-1)(a-b)^2\) ,
it is proved that given the prior distribution \(\mathrm {P}\) , for any confidence parameter \(\delta \in (0,1)\) , with probability at least \(1-\delta \) ,
\(2(\mathrm {M}-1) \left( \mathbb {E}_{W\sim \mathrm {Q}_i}\left[ \mathrm {L}_{\mathrm {P}_{Z|t_i}}(W)-\mathrm {L}_{\mathbf {Z}_i^{\mathrm {M}}}(W)\right]\right)^2 \le \mathrm {D}\left(\mathrm {Q}_i||\mathrm {P}\right)+\log \left(\frac{\mathrm {M}}{\delta }\right). \) 
